1. Field of the Invention
The present invention relates to a method of manufacturing a semiconductor device such as a semiconductor integrated circuit (hereinafter referred to as an IC), and more particularly, to a substrate processing apparatus for forming a desired film on a substrate such as a semiconductor wafer (hereinafter referred to as a wafer) on which devices such as an IC will be formed, and a method of manufacturing a semiconductor device such as an IC.
2. Description of the Prior Art
In a method of manufacturing an IC, a batch type vertical apparatus may be used to form a film. For example, referring to Patent Document 1, in a semiconductor device manufacturing process, when a film is formed using an amine-based material, for example, by an atomic layer deposition (ALD) method, a titanium (Ti) source and a nitrogen (N) source are alternately supplied to a semiconductor silicon substrate disposed in a processing chamber so as to form a TiN film. For a change from Ti source to N source, purging is performed using hydrogen (H2) so as to remove the Ti source from the processing chamber, and for a change from N source to Ti source, purging is performed using H2 so as to remove the N source from the processing chamber.
[Patent Document 1]    Japanese Unexamined Patent Application Publication No. 2006-269532
For example, in the case of a substrate processing apparatus configured to form a film by alternately supplying sources (A) and (B) to a substrate disposed in a processing chamber so that the molecules of the sources can be adsorbed on the substrate, when one of the sources is supplied but the other is not yet supplied, it is necessary to remove the former source from the processing chamber and the surface of the substrate. in a conventional method, to remove a source from the inside of the processing chamber or the like, hydrogen (H2) gas or inert gas such as nitrogen (N2) gas is continuously or intermittently supplied to the inside of the processing chamber while exhausting the inside of the processing chamber. In such a method, however, it takes long time to remove surplus source molecules adsorbed on a part such as the surface of a substrate, and as a result, productivity decreases. Moreover, in a conventional purge method, if purge time is reduced, purging is insufficiently performed, and as a result, film thickness is increased.